android - 如何在android中将对象值绘制到 ListView 中

Question

如何从使用对话框构造的对象中提取值并将它们放入 ListView 中。

例如；我有一个对象叫做

digitalControlObject(int, int, bool, bool).

现在，当用户通过具有相应输入 UI 的对话框构造这些对象时 (int, int, bool, bool)

我想获取这些对象并将它们添加到 ListView 中 - 然后它将用相应的 (int, int, bool, bool) 为该对象填充四行

例如第一行是这样的:

Table Row |Pin Number |Pin Type |Pin Status |Pin Mode
------------------------------------------------------
Row 1     | 13        | 0       | ON        | ON

所以；例如，每当我点击 ListView 旁边的按钮时；对话框将出现并允许我构建另一个 digitalControlObject... 然后当我提交该对话框时，它应该附加另一行与该数据集对齐。

编辑:

所以我尝试将其作为代码:

    package com.example.ioiocontroller;

import java.util.ArrayList;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ListView;

public class digitalFragment extends Fragment {
    ArrayList<digitalControlObject> digitalList;
    ListView digitalListView;
    View digitalFragmentView;
    ArrayAdapter listAdapter;
    Button addDigital;
    Button removeDigital;
    public digitalFragment() {
        // TODO Auto-generated constructor stub
    }

    public View onCreateView(LayoutInflater viewInflation, ViewGroup container,
            Bundle SavedInstantState) {



        digitalFragmentView = viewInflation.inflate(
                R.layout.digitalfragment_page, container, false);

        addDigital = (Button) digitalFragmentView
                .findViewById(R.id.digitalAddition);
        removeDigital = (Button) digitalFragmentView
                .findViewById(R.id.digitalRemoval);
        digitalListView = (ListView) digitalFragmentView
                .findViewById(R.id.digitalListView);

        // ADDITION CLICK METHOD FOR DIGITAL IO
        addDigital.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                    listAdapter = new ArrayAdapter(getActivity(), R.layout.digitallistview_layout);
                    digitalListView.setAdapter(listAdapter);
                    digitalList.add(new digitalControlObject(0, true, true, 0));


                    listAdapter.notifyDataSetChanged();
                // create and pass the digitalControlObject to the main activity

            }
        });

        // REMOVAL CLICK METHOD FOR DIGITAL IO
        removeDigital.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

            }
        });

        return digitalFragmentView;
    }

    public ListView getDigitalListView() {
        return digitalListView;
    }

    public void setDigitalListView(ListView digitalListView) {
        this.digitalListView = digitalListView;
    }

    public View getDigitalFragmentView() {
        return digitalFragmentView;
    }

    public void setDigitalFragmentView(View digitalFragmentView) {
        this.digitalFragmentView = digitalFragmentView;
    }

}

但是，当我编译并运行并点击 onclick View 的按钮时，我得到一个空指针错误？

编辑 2:

即使进行了这些更改，它也不起作用；这是我最近的代码......我仍然得到一个空指针

public View onCreateView(LayoutInflater viewInflation, ViewGroup container,
            Bundle SavedInstantState) {

        digitalFragmentView = viewInflation.inflate(
                R.layout.digitalfragment_page, container, false);

        addDigital = (Button) digitalFragmentView
                .findViewById(R.id.digitalAddition);
        removeDigital = (Button) digitalFragmentView
                .findViewById(R.id.digitalRemoval);
        digitalListView = (ListView) digitalFragmentView
                .findViewById(R.id.digitalListView);
        listAdapter = new ArrayAdapter(getActivity(), R.id.digitalListView);
        digitalListView.setAdapter(listAdapter);

        // ADDITION CLICK METHOD FOR DIGITAL IO
        addDigital.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                digitalList.add(new digitalControlObject(0, true, true, 0));

                listAdapter.notifyDataSetChanged();
                // create and pass the digitalControlObject to the main activity

            }
        });

        // REMOVAL CLICK METHOD FOR DIGITAL IO
        removeDigital.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

            }
        });

        return digitalFragmentView;
    }

编辑 3:

有了这个最新的代码，我瞬间崩溃了

    package com.example.ioiocontroller;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;

public class digitalFragment extends Fragment {
    ArrayList<String> digitalList;
    ListView digitalListView;
    View digitalFragmentView;
    Button addDigital;
    Button removeDigital;

    public digitalFragment() {
        // TODO Auto-generated constructor stub
    }

    public View onCreateView(LayoutInflater viewInflation, ViewGroup container,
            Bundle SavedInstantState) {

        digitalFragmentView = viewInflation.inflate(
                R.layout.digitalfragment_page, container, false);

        addDigital = (Button) digitalFragmentView
                .findViewById(R.id.digitalAddition);
        removeDigital = (Button) digitalFragmentView
                .findViewById(R.id.digitalRemoval);
        digitalListView = (ListView) digitalFragmentView
                .findViewById(R.id.digitalListView);
        final MyAdapter adapter = new MyAdapter(getActivity(), R.id.title, digitalList);
        digitalListView.setAdapter(adapter);;

        // ADDITION CLICK METHOD FOR DIGITAL IO
        addDigital.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                digitalList.add("TEST");

                adapter.notifyDataSetChanged();
                // create and pass the digitalControlObject to the main activity

            }
        });

        // REMOVAL CLICK METHOD FOR DIGITAL IO
        removeDigital.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

            }
        });

        return digitalFragmentView;
    }

    public ListView getDigitalListView() {
        return digitalListView;
    }

    public void setDigitalListView(ListView digitalListView) {
        this.digitalListView = digitalListView;
    }

    public View getDigitalFragmentView() {
        return digitalFragmentView;
    }

    public void setDigitalFragmentView(View digitalFragmentView) {
        this.digitalFragmentView = digitalFragmentView;
    }
//////////////////////////////////////////////////////////////////////////////////
    public class MyAdapter extends ArrayAdapter<String> {

        private Context context;

        public MyAdapter (Context context, int textViewResourceId, List<String> items) {
            super(context, textViewResourceId, items);
            this.context = context;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            View view = convertView;
            if (view == null) {
                LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                view = inflater.inflate(R.layout.item_row, null);
            }

            String item = getItem(position);
            if (item!= null) {
                TextView itemView = (TextView) view.findViewById(R.id.title);
                if (itemView != null) {
                    itemView.setText("Item: " + item + " in position " + position);
                }
             }

            return view;
        }
    }

}

这是日志:

02-27 12:58:10.173: E/Trace(9958): error opening trace file: No such file or directory (2)
02-27 12:58:10.173: D/jdwp(9958): sendBufferedRequest : len=0x4B
02-27 12:58:10.190: D/dalvikvm(9958): open_cached_dex_file : /data/app/com.example.ioiocontroller-1.apk /data/dalvik-cache/data@app@com.example.ioiocontroller-1.apk@classes.dex
02-27 12:58:10.193: D/ActivityThread(9958): BIND_APPLICATION handled : 0 / AppBindData{appInfo=ApplicationInfo{417cecb8 com.example.ioiocontroller}}
02-27 12:58:10.262: D/dalvikvm(9958): GC_FOR_ALLOC freed 54K, 11% free 6279K/7027K, paused 19ms, total 19ms
02-27 12:58:10.268: I/dalvikvm-heap(9958): Grow heap (frag case) to 7.678MB for 1536016-byte allocation
02-27 12:58:10.289: D/dalvikvm(9958): GC_FOR_ALLOC freed 1K, 10% free 7778K/8567K, paused 20ms, total 20ms
02-27 12:58:10.310: D/dalvikvm(9958): GC_CONCURRENT freed <1K, 10% free 7778K/8567K, paused 2ms+2ms, total 21ms
02-27 12:58:10.337: D/ActivityThread(9958): ACT-AM_ON_RESUME_CALLED ActivityRecord{417d02e0 token=android.os.BinderProxy@417cfaa8 {com.example.ioiocontroller/com.example.ioiocontroller.MainActivity}}
02-27 12:58:10.344: D/ActivityThread(9958): ACT-LAUNCH_ACTIVITY handled : 0 / ActivityRecord{417d02e0 token=android.os.BinderProxy@417cfaa8 {com.example.ioiocontroller/com.example.ioiocontroller.MainActivity}}
02-27 12:58:10.365: D/AbsListView(9958): checkAbsListViewlLogProperty get invalid command
02-27 12:58:10.366: D/AndroidRuntime(9958): Shutting down VM
02-27 12:58:10.366: W/dalvikvm(9958): threadid=1: thread exiting with uncaught exception (group=0x411b7908)
02-27 12:58:10.370: E/AndroidRuntime(9958): FATAL EXCEPTION: main
02-27 12:58:10.370: E/AndroidRuntime(9958): java.lang.NullPointerException
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.widget.ArrayAdapter.getCount(ArrayAdapter.java:330)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.widget.ListView.setAdapter(ListView.java:466)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at com.example.ioiocontroller.digitalFragment.onCreateView(digitalFragment.java:41)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.app.Fragment.performCreateView(Fragment.java:1500)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1467)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:472)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.view.ViewPager.populate(ViewPager.java:1068)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1436)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.View.measure(View.java:15264)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4918)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.View.measure(View.java:15264)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.widget.LinearLayout.measureVertical(LinearLayout.java:833)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.View.measure(View.java:15264)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4918)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2163)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.View.measure(View.java:15264)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2131)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1242)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1435)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1127)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4650)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:747)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.Choreographer.doCallbacks(Choreographer.java:567)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.Choreographer.doFrame(Choreographer.java:536)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:733)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.os.Handler.handleCallback(Handler.java:615)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.os.Handler.dispatchMessage(Handler.java:92)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.os.Looper.loop(Looper.java:153)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at android.app.ActivityThread.main(ActivityThread.java:4987)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at java.lang.reflect.Method.invokeNative(Native Method)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at java.lang.reflect.Method.invoke(Method.java:511)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)
02-27 12:58:10.370: E/AndroidRuntime(9958):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

您应该创建一个具有自定义行布局的 ListView，其中包含四个 TextView，您可以在其中放置数据。一些例子 here和 here .通过这种方式，您可以创建如下内容:

然后你只需要继续向你的 ListAdapter 添加数据以向 ListView 添加新行

---

响应您编辑的答案，没有 Logcat 是一个猜测，我认为问题出在这里:

listAdapter = new ArrayAdapter(getActivity(), R.layout.digitallistview_layout);

最好的测试方法是为 ListView 中的每一行创建一个带有 row_layout.xml 的简单适配器:

public class MyAdapter extends ArrayAdapter<String> {

    private Context context;

    public MyAdapter (Context context, int textViewResourceId, List<String> items) {
        super(context, textViewResourceId, items);
        this.context = context;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        View view = convertView;
        if (view == null) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = inflater.inflate(R.layout.item_row, null);
        }

        String item = getItem(position);
        if (item!= null) {
            TextView itemView = (TextView) view.findViewById(R.id.title);
            if (itemView != null) {
                itemView.setText("Item: " + item + " in position " + position);
            }
         }

        return view;
    }
}

这将是您的 xml item_row.xml 布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

<TextView 
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/title"/>

</LinearLayout>

所以要使用这个:

digitalList.add(new digitalControlObject(0, true, true, 0));

MyAdapter adapter = new MyAdapter(getActivity(), R.id.title, digitalList);
digitalListView.setAdapter(adapter);

而且这个 digitalList 必须在您的 digitalfragment_page 布局中，因为这是您在 Fragment

中膨胀的那个